Western pond turtle
Western pond turtle | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Reptilia |
Order: | Testudines |
Suborder: | Cryptodira |
Superfamily: | Testudinoidea |
Family: | Emydidae |
Genus: | Actinemys |
Species: | A. marmorata[1]
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Binomial name | |
Actinemys marmorata[1] | |
The range of the western pond turtle. | |
Synonyms[4] | |
The western pond turtle (Actinemys marmorata), also known commonly as the Pacific pond turtle is a species of small to medium-sized turtle in the family Emydidae. The species is endemic to the western coast of the United States and Mexico, ranging from western Washington state to northern Baja California. It was formerly found in Canada (in British Columbia), but in May 2002, the Canadian Species at Risk Act listed the Pacific pond turtle as being extirpated.
Taxonomy and systematics
Its genus classification is mixed.
Description
The
Distribution
The western pond turtle originally ranged from northern
Ecology and behavior
The western pond turtle occurs in both permanent and intermittent waters, including marshes, streams, rivers, ponds, and lakes. It favors habitats with large numbers of emergent logs or boulders, where individuals aggregate to bask. They also bask on top of aquatic vegetation. Consequently, this species is often overlooked in the wild. However, it is possible to observe resident turtles by moving slowly and hiding behind shrubs and trees.
A. marmorata can be encouraged to use artificial basking substrate, or rafts, which allows for easy detection of the species in complex habitats.
In addition to its aquatic habitat, terrestrial habitat is also extremely important for the western pond turtle. Since many intermittent ponds can dry up during summer and fall months along the west coast, especially during times of drought, the western pond turtle can spend upwards of 200 days out of water. Many turtles overwinter outside of the water, during which time they often create their nests for the year. Overwintering sites can sometimes be 500 meters from a main body of water [6]
Diet
The western pond turtle is
Predation and threat
Raccoons, otters, ospreys, and coyotes are the biggest natural threats to this turtle, its eggs, and hatchlings. Weasels and large fish are also known predators.[7] Non-native predators include bullfrogs, crayfish, and opossums.
In the past the turtle was exploited as food by both indigenous peoples and American settlers. After the goldrush in California a large "fishery" emerged processing turtles from the San Francisco Bay Estuary into canned soup for markets East.
Finally, this species is still threatened by humankind. Due to habitat destruction and modification, this species is currently listed as vulnerable on the IUCN Red List and by NatureServe. It also faces significant competition from introduced invasive species, especially the red-eared slider. With the removal of ponds, modification of sandy banks needed for egg laying, draining of wetlands, this species is now vulnerable. Efforts at reintroducing this turtle to its native range have met with limited success.
Reproduction
Sexually mature females of the western pond turtle produce 5–13 eggs per clutch. They deposit eggs either once or twice a year. They may travel some distance from water for egg-laying, moving as much as 0.8 km (1/2 mile) away from and up to 90 m (300 ft) above the nearest source of water, but most nests are within 90 m (300 ft) of water. The female usually leaves the water in the evening and may wander far before selecting a nest site, often in an open area of sand or hardpan that is facing southwards. The nest is flask-shaped with an opening of about 5 cm (2 in). Females spend considerable time covering up the nest with soil and adjacent low vegetation, making it difficult for a person to find unless it has been disturbed by a predator.
Hatchlings
The vast majority of western pond turtle hatchlings overwinter in the nest, and this phenomenon seems prevalent in most parts of the range, especially northern areas. This might explain the difficulty researchers have had in trying to locate hatchlings in the fall months. Winter rains may be necessary to loosen the hardpan soil where some nests are deposited. It may be that the nest is the safest place for hatchlings to shelter while they await the return of warm weather. Whether it is hatchlings or eggs that overwinter, young first appear in the spring following the year of egg deposition. Individuals grow slowly in the wild, and their age at their first reproduction may be 10 to 12 years in the northern part of the range. The western pond turtle may survive more than 50 years in the wild.
References
- ^ Rhodin 2010, p. 000.105
- . Retrieved 29 December 2023.
- ^ "Actinemys marmorata. NatureServe Explorer 2.0". explorer.natureserve.org. Retrieved 9 December 2022.
- ^ Species Actinemys marmorata at The Reptile Database . www.reptile-database.org.
- ^ Rhodin 2010, p. 000.139
- ^ Reese, D. A.; Jr..Welsh, Hartwell H. (1997). "Use of terrestrial habitat by western pond turtles (Clemmys marmorata): implications for management". Pages 352-357 in Proceedings: Conservation, Restoration, and Management of Turtles and Tortoises. An International Conference. New York Turtle and Tortoise Society.
- ^ "Wildscreen Arkive". arkive.org. Archived from the original on 23 January 2009. Retrieved 26 April 2016.
Bibliography
- Holland, Dan C., PhD. The Western Pond Turtle: Habitat and History, Final Report. U.S. Department of Energy, Bonneville Power Administration, Division of Fish and Wildlife; Wildlife Diversity Program, Oregon Department of Fish and Wildlife, August 1994.
- Rhodin, Anders G.J.; van Dijk, Peter Paul; Iverson, John B.; Shaffer, H. Bradley (2010-12-14). "Turtles of the World 2010 Update: Annotated Checklist of Taxonomy, Synonymy, Distribution and Conservation Status" (PDF). Archived (PDF) from the original on 2011-07-17. Retrieved 2010-12-15.
- "Western pond turtle (Actinemys marmorata)". Wildscreen ARKive. Archived from the original on 1 February 2019. Retrieved April 25, 2016.
Further reading
- Baird SF, Girard CF (1852). "Descriptions of new species of Reptiles, collected by the U. S. Exploring Expedition under the command of Capt. Charles Wilkes, U. S. N. First part.—Including the species from the Western coast of America". Proc. Acad. Nat. Sci. Philadelphia 6: 174–177. (Emys marmorata, new species, p. 177).
- Seidel, Michael E.; Ernst, Carl H. (2017). "A Systematic Review of the Turtle Family Emydidae". Vertebrate Zoology 67 (1): 1–122. (Actinemys marmorata, pp. 36–38, Figure 36).